For those of us who still play OW or will continue to do so, what would make you quit the game for good? 
For me it would be OW becoming P2W
For example OP heroes which could only be obtain by purchasing them, prammo (premium ammunition), extra health, etc.
Now that we know that heroes will be locked behind grindy BPs, I wouldnāt be surprised if they did add any of this stuff.
If OW does become P2W then I would just pull chocks and go my merry way! 
The only think that would make me quit is if they remove the workshop/custom games
If all else fails, I at least have that to fall back to, at least workshop modes are fun
Dunno.
Tbh, theyād have to do something beyond tolerable, and there would need to be another game Iād be interested in playing instead.
That said, the stuff that would probably annoy me most would probably be gameplay related, or deliberarely sabotaging queue times.
OW2 in itās current state: f2p, 5v5, massive gulf between the good heroes and the bad, 2cp being removed rather than koth.
These are all massive negatives that are adding up to something I dont want to play.
Skins being priced at 20$ and four entire seasons of never missing a week of overly grindy challenges to earn that much. Itās absurdly bad.
If they donāt give at all on that score, I donāt see myself sticking around for Season 2.
lucio being nerfed or bap being buffed
If they release this game with current P2W mechanics. I dont want to grind thousand of years for a Hero.
Give me my money back for OW1
Ok, what would make me quit is if the game straight up Titanflopped meaning the population gets so low that the match quality becomes total garbage.
That or the game becomes Bot Fortress 2 where itās infested with hackers that destroy the game. For instance, Iād go back and play a little bit of Black Ops 2 right now just as a throwback, but I know that the servers are all hacked so the likelyhood of finding a working match are low.
In other words, if Overwatch does ādieā I wonāt be following the ship straight underwater, but Iām gonna hang on to the mast of the ship until I have to jump off and swim.
Not enjoying it anymore would make me quit. Vague answer, I know. But I donāt know what specifically would cause me to lose enjoyment. Despite all the problems that have plagued Overwatch, when I boot it up and start playing, I still enjoy it. So I continue to play it.
That said, during Moth Meta, I hated that meta so much that I quit for the remainder of that metaās duration. So I at least know that certain metas can cause me to quit.
New games and playing other multiplayer games with my friends.
So itās not so much I quit Ow or OW 2 more than it is I prefer playing new stuff with friends first. Ow you way lower on my gaming to do list.
None of my OW irl friends are playing nor interested in 2.
Tuesday I will see if any gamers on my friend list will return.
The phone thing possibly. Iām poor and use MetroPCS, and for some reason my phone works but my husbandās doesnāt as āprepaidā with the same carrier. It feels like āyou donāt have phones?ā part 2 electric boogaloo.
Iām really not going to get an expensive phone contract just to play overwatch. Thatād be ridiculous.
It already happened with the massive nerfs to doomfist. Only reason I play this game anymore. Between that, the season pass, mtx, and more it just shows how out of touch the devs are and they only care about money.
Oddly enough they only have jobs because of the player base. Piss off enough of us and the game will flop and they are done. Jeff has gota be rollin his eyes right now while writing his movie script
If they ever decide to quit making waifus the game will end
If it actually does go p2w, I think that would be enough. But just asking to play the game for the new hero doesnāt bother me. Maybe Iāll get less free skins, so I play a bit less. But OW is just fun.
More long range oneshots.
Deleting any heroes, reworking them in insultingly bad ways, introducing pay to win (like you said), returning 2cp
Oh this isnāt for me.
But, Iād quit playing if queue times were too long. Which is why I quit Ow1
Itās still f2p but has a p2w fast track system
If they continue to make decisions that are more to benefit the pro play and highest levels of play. I think a lot of the buffs they have done for that have been on a basis where they lack the fundamental understanding of why things are being used more or less in Pro play based on the past. Thatās kind of been a constant within blizzard.
Iām not saying they shouldnāt look to balance things, but they should have an actual understanding why there is a discrepancy between say the average player and the top level of players on a certain hero not just flat buff/nerf dps/heal etc.
Once i have no friends that might ask me to play OW with them, game is gone from my pc.